Circuit interrupter



Sept- 1944- w. M. LEEDS CIRCUIT INTERHUPTER Filed Aug. 12, 1942 s Sheets-Sheet 1 WITNESSES: I I INVENTOR 4%,. MHz/m M. Leeds.

p 1944- w. M. LEEDS 2,359,127

CIRCUIT INTERRUfTER i i 13 u Li WITESSES. I 33. I l NTOR MZM, WZ'NZ/Yrq Leeds.

Sept. 26, 1944,

LEEDS CIRCUIT INTERRUPTER Filed Au 12, 1942 f g im 5 Sheets-Sheet 4 Cggf ml 7 (b 101 EA 22, my 1 101 WITNESSES: 123' m INVENTOR 1 (4 WinZ/zrop M Leeds.

BY 2J1? M R/ALWV A ATTO RNE Sept. 26, 1944. w LEEDS 2,359,127

GIRCUIT INTERRUPTER- Filed Aug. 12, 1942 5 sheets-sheet 5 I WL: 3 91 WITNESSES:

s W277 27770 9 M Leeds.

Patented Sept. 26, 1944 CIRCUIT INTERRUPTER Winthrop M. Leeds, Wilkinsburg, Pa., assignor to Westinghouse Electric & Manufacturing Company, East Pittsburgh, Pa., a corporation of Pennsylvania Application August 12, 1942, Serial No. 454,515

31 Claims.

This invention relates to circuit interrupters in general, and, more particularly, to are extinguishing structures therefor.

More specifically, the present invention concerns a method, structure and mechanism for effecting a rapid extinguishment of the are which is drawn upon the opening of the contacts of a circuit interrupter.

Test results on various types of arc rupturing devices indicate that the interrupting effectiveness measured in volts per inch of break distance increases somewhat with increasing applied voltage. For instance, a given current at 132 kv. may be interrupted, using a conventional two break interrupter, with only twice the break distance that is required to interrupt the same current at 33 kv., although in the former case the voltage is four times as great as in the latter case.

If, however, instead of using the conventional two break contact arrangement, eight breaks are opened simultaneously, it is found that the total break distance in all of the breaks required to interrupt a given current at 132 kv. is about four times the break distance for the same current at 33 kv., with the conventional two break contact arrangement. In other words, the same results are obtained as might be expected if four separate 33 kv. two break circuit breakers were connected in series and operated simultaneously to interrupt the same current at 132 kv.

In terms of total break distance required for are extinction, the eight break arrangement for 132 kv. is only one-half as effective as the two break arrangement for 132 kv. In terms of arcing time, however, the eight break design will clear the circuit twice as fast as the two break design, 1. e., in one-half the time assuming the same lift rod speed.

It would, therefore, seem that the ideal arrangement would be to use as few breaks as possible, only one break preferably, provided that the required break distance can be obtained very rapidly. Instead of using greatly increased mechanical contact opening speeds, I propose to draw a multiplicity of short serially relates arcs which will almost immediately thereafter merge into a single arc.

I accomplish the foregoing by utilizing a pluing structure. Upon the lateral separation of the movable bridging contacts, a multiplicity of serially related arcs are drawn between the moving bridging contacts, but almost immediately, due to the ionization of the arcing space, the plurality of serially related arcs merge into a single are which extends between the main contacts of the interrupter.

The main contacts of the interrupter may be stationary, or one of the main contacts may be movable and the operating mechanism arranged in such a manner that the lateral separation of the movable bridging contacts is effective simultaneously with the opening movement of the movable main contact away from the stationary main contact.

In my invention there may also be provided a plurality of insulating bafiies which may cause the arc to be lengthened in a zigzag path, first as a number of short arcs in series, and then as a single arc. The single arc may be extinguished by the deionizing action of a turbulent gas-blast passing axially through the arc extinguishing structure.

Thegeneral principle of my invention, that is, establishing very rapidly an are between two main contact members may be applied to many conventional arc extinguishing structures already well known to the art, and it is also susceptible to a number of modifications which may actually improve the operation of these conventional devices in terms of required break distance to extinguish an arc.

For instance, it is known that in any arc rupturing device employing a chamber type are interrupting structure from which a bayonet-type contact is Withdrawn, the interrupting effectiveness is improved by making the diameter of the bayonet-type contact and the diameter of the chamber opening as small as possible. In the interrupting structure of my invention the effective cross-section of the opening through the structure may be made quite small without reducing the normal current carrying capacity of the contacts, particularly if one or more bafiles are extended into notches or recesses in the faces of the intermediate movable bridging contacts.

Additional effectiveness may be obtained in the arc interrupting structure of my invention by utilizing a plurality of bafiles which give a crossblast action to the gases with respect to the are as the gases follow the zigzag path through the interrupting structure.

Also in the interrupting structure of my invem tion the motion of the movable intermediate bridging contacts may be used to force liquid, such as oil, from oil pockets into the arcing region.

My invention is applicable to liquid breakers or to gaseous breakers, such as the air-break type. In applying my invention to a liquid breaker, the movement of the intermediate bridging contacts may be utilized to create piston action to force liquid, such as oil, along the axis of the interrupting structure.

My invention is also susceptible to application in gaseous type interrupters which use a gas evolving material. When my invention is used in such an application the insulating bafiles may be made of a gas evolving material which, upon contact with the arc, give forth a large amount of arc extinguishing gas to facilitate the extinction of the arc.

My invention may also be easily applied to are interrupting structures of the grid type, that is, the arc which is rapidly produced in my invention may be easily laterally transferred into a grid structure employing magnetic means to laterally move the arc and to effect its extinction.

Upon an understanding of my invention it will be readily apparent to one skilled in the art that its uses in conventional interruptin structures are manifold, and that numerous applications of it will readily suggest themselves.

It is one of the objects of my invention to provide an improved method of arc interruption whereby an arc of relatively long dimensions is much more rapidly produced than in conventional structures and the lengthened arc is quickly subjected to the deionizing action of gaseous or liquid particles to effect its extinction.

Another object of my invention is to provide in a liquid breaker a novel structure for producing very rapidly an arc of relatively long dimensions, which are may be subjected immediately to the deionizing action of liquid particles.

Another object of my invention is to provide a circuit interrupter of the air-break type in which an arc is very rapidly lengthened and mad to react upon gas evolving material to result in the production of arc extinguishing gas to be used in effecting the extinction of said arc.

Another object of my invention is to utilize my invention in conjunction with well known interrupting structures so that the arc after it is once quickly produced and lengthened, may be acted upon by the extinguishing action of conventional interrupting structures.

Another object of my invention is to provide an improved arc interrupting structure of either the liquid or gaseous type of chamber form, from which a movable bayonet-type contact is with drawn, and in such a structure to reduce the effective crosssection of the arc extinguishing passage as much as possible, yet having the current carrying capacity of the interrupter um'mpaired.

Another object of my invention is to provide in an interrupting structure a rapidly produced arc of considerable length by the use of a plurality of intermediate movable bridging blocks which, when laterally separated, draw a plurality of serially related arcs which immediately coalesce into a single arc of considerable length because of the ionization of the arcin region.

Another object of my invention is to provide means in an interrupting structure for the production of a plurality of serially related arcs, which arcs extend in a zigzag path, and which arcs tend to merge into a single arc of considerable length which extends along a zigzag path.

Another object of my invention is the provision of an interrupting structure in which is provided two main contacts bridged by a plurality of laterally movable contact blocks, an are being rapidly produced between the main contacts by the lateral separation of the intermediate contact blocks, and the motion of the lateral separating contact blocks being utilized to force liquid or gaseous particles into the arcing region between the main contacts of the interrupting structure.

Another object is to provide an improved operating mechanism in a circuit breaker of the foregoing type.

I am well aware that modifications of my invention are innumerable, and by my illustrating these embodiments of my invention I do not intend to limit its scope, or to suggest that there are not many other modifications which would readily suggest themselves to one skilled in the art.

Further objects and advantages will be apparent upon consideration of the following specification, taken in connection with the accompanying drawings, in which:

Figure 1 is a side elevational view, partly in section, of a circuit interrupter embodyin my invention and shown in the closed-circuit position;

Fig. 2 is a cross-sectional view taken on the line II-II of Fig. 1, and looking in the direction of the arrows;

Fig. 3 is an elevational end view taken at right angles to the view shown in Fig. 1;

Fig. 4 is a reduced plan view of one of the insulating plates used in the circuit breaker shown in Fig. 1;

Fig. 5 is a cross-sectional view, taken on the line VV of Fig. 4, and looking in the direction of the arrows;

Fig. 6 is a reduced plan view of two cooperating strips used in the grid structure of the circuit breaker shown in Fig. 1;

Fig. '7 is a cross-sectional view taken on the line VII-V]I of Fig. 6, and looking in the direction of the arrows;

Fig. 8 is a reduced plan view of another insulating plate used in the grid structure of Fig. 1;

Fig. 9 is a cross-sectional View on the line IX-IX of Fig. 8, and looking in the direction of the arrows;

Fig. 10 is a cross-sectional view of a modification of my invention taken on the line XX of Fig. 25;

Figs. 11 through 24 are plan and cross-sectional views of the insulating plates used in the modification of my invention shown in Fig, 10;

Fig. 2.5 is a cross-sectional view taken on the line XXVXXV of Fig. 10, but showing the interrupter in the open-circuit position;

Fig. 26 is a side elevational view of a modified type of circuit interrupter embodying my invention; and

Fig. 27 is an enlarged side elevational view, partly in section, of the modified type of circuit interrupter shown in Fig. 26.

Referring to the embodiment of my invention shown in Figs. 1 to 9, inclusive, and referring particularly to Fig. 1, the reference numeral I designates one of two vertically disposed insulating support plates. The other of the two vertically disposed support plates is shown in Figs. 2 and 3 and is designated by the reference numeral 2. Referring particularly to Fig. 2, there is shown an arcing grid chamber disposed between the two vertically disposed support plates I, 2, and designated generally by the reference numeral 5. The arcing grid chamber 5 comprises a plurality of suitably shaped insulating plates, the configuration of which are clearly shown in Figs. 4 to 9, inclusive, and to be described more fully hereinafter. The insulating plates comprising the arcing grid chamber 5 are pressed together between two insulating end plates 4 and 6 by the tie-rods I. Two insulating base plates 8, 9 are secured by screws I to the insulating end plates 4, 6. The arcing grid chamber is rigidly secured between the vertically disposed support plates I, 2 by screws I I which terminate in the insulating base plates 8, 9.

A plurality of intermediate laterally movable contact blocks I2 are alternately disposed within the arcing grid chamber 5 to contact one another in the closed-circuit position of the interrupter, as shown in Fig. 1, to provide a current conducting path through the arcing grid chamher 5. Each of the contact blocks I2 is rectangular in shape with the face I4 thereof rounded to make line contact with the adjacently disposed contact blocks l2. Each of the contact blocks I2 is resiliently mounted upon an operating rod I3 for reciprocating lateral movement within the arcing grid chamber 5.

The resilient connection between the contact block I2 and the operating rod [3 is provided by the utilization of a compression spring I5, as more clearly shown in Fig. 2. A U-shaped metallic member [1 is welded to each operating rod I3 and provides a support for one end of the comto two link members 48, 49. The upper ends of the link members 48, 49, as viewed in Fig. 1, are pivotally secured by a pivot pin 5| to a second bifurcated lever 53, which itself is pivotally mounted about a fixed pin 55 extending transversely through the support plates I, 2. The lefthand end of the bifurcated lever 53, as viewed in Fig. 1, is pivotally secured by means of a pivot pin 51 to two insulating link members 58, 59, the lower ends of which are pivotally secured by means of a pivot pin 6I to the upper insulatextends loosely into a hole I9 (see Fig. 2) bored into the lower surface of the contact block I2. A pin 2| extends snugly transversel through the end of the operating rod I3. The pin 2|, however, extends loosely through an aperture 23 drilled laterally through the contact block l2. It will therefore be readily apparent that a certain degree of resilience is provided by the compression spring I5 depending upon the relative 1 diameters of the pin 2| and the aperture 23.

The operating rods I3 extending through the lower insulating base plate 9 are rigidly secured to an insulating operating block 25. The operating rods I3 extending upwardly through the upper insulating base plate 8 also are rigidly secured to an insulating operating block 26.

The insulating operating block 25 is pivotally secured by a pin 21 to two insulating links 28, 29, the lower ends of which are pivotally mounted by a pin 31 to a bifurcated lever 33, as more clearly shown in Fig. 1. The bifurcated lever 33 is rotatable about a fixed pivot pin 35, which extends through both vertically disposed support plates I, 2.

The bifurcated lever 33 is pivotally operable about the fixed pivot pin 35 by means of two link members 36, 3! (see Fig. 3) which are pivotally mounted by means of a pin 39 to the righthand end of the bifurcated lever 33 as viewed in Fig, 1. The upper ends of the link members 35, 31, as viewed in Fig. 1, are pivotally mounted by a pin M to two lever members 42, 43. The lever members 42, 43 are pivotally movable about a fixed pivot pin 45 which extends through the support plates I, 2. The right-hand ends of the lever members 42, 43, as viewed in Fig. 1, are

pivotally connected by means of a pivot pin 41 ing operating block 26.

A tension spring 63 is extended between the pivot pins 5I and 4I. It will therefore be seen that the tension sprin 63 tends to maintain the interrupter in the open circuit position because of the biasing action exerted by the tension spring '63 on the bifurcated levers 33, 53.

Referring particularly to Fig. 3, it will be noted that two contact fingers 64, are secured on opposite sides of a conducting block 61 and maintained in compressive relation by means of leaf springs 68, 69. The leaf springs 68, 69, which maintain the fingers; 64, 55 in compressive relation, are mounted upon a threaded stud II (see Fig. 3) which extends through the conducting block 6! and also through two lever members I3, I5. The left-hand ends of the lever members I3, I5, as viewed in Fig. l, are pivotally mountedon a fixed pivot pin l! which extends transversely through the support plates I, 2.

The pivot pin 41 which pivotally connects the lever members 42, 43, respectively, with the link members 48, 49 also extends loosely through the upper portion of the conducting block 61. It will therefore be readily apparent that by virtue of the fixed pivot pins 45, 11 there will be no lateral movement of the conducting block 61 during its upward and downward movement, as viewed in Fig. l.

A lift rod I9, composed of insulating material, has at its lower end a conducting bridging member 8| (only a fragmentary part of which is shown Iin Fig. l), the left-hand end of which. as viewed in Fig. 1, being adapted to engage the contact fingers 64, B5 to separate them and to abut against the lower portion of the conducting block 61 at the point designated by the reference numeral 83 in Fig. l.

When it is desired to close the electrical circuit through the interrupter shown in Fig, 1, the insulating lift rod I9 is actuated upwardly by external operating mechanism (not shown). The upward movement of the insulating lift rod I9 also moves upwardly the conducting bridging member BI. The conducting bridging member SI separates the contact fingers 64, 65 and engages the lower portion of the conducting block 61 at 83 (see Fig. 1) to move the conducting block 61 upwardly to result in a counterclockwise rotation of the lever members 42, 43 about the fixed pivot pin 45. This counterclockwise rotation of the lever members 42, 43 about the fixed pivot pin 45 causes, by virtue of the link members 48, 49 and 36, 3I, pivotal motion of the bifurcated levers 33, 53 to result in a closing engagement of the contact blocks l2.

During the closed-circuit position of the interrupter, which is illustrated in Fig. l, the electrical circuit therethrough comprises the external line terminal 85, the conducting adaptor 91, the conducting strap 89, the left-hand stationary contact 9|, the contact blocks I2, the right-hand stationary contact 93, the flexible conductor 95, the conducting block 61, the contact fingers 64,

65, the conducting bridging member iii to the right-hand grid structure of the interrupter (not shown) which is identical to the left-hand grid structure shown in Fig. 1. Both, grid structures may be placed in a suitable tank, not shown.

When it is desired to open the interrupter shown in Fig. 1, or when external overload conditions exist in the electrical circuit connected to the interrupter, suitable external operating mechanism (not shown) is actuated to result in downward motion of the insulating lift rod 19. The downward motion of the insulating lift rod 19 permits the tension spring 63 to draw the two pivot pins i, M partially toward each other and hence to result in opening movement of the bifurcated levers 33, 53. The opening movement of the bifurcated levers 33, 53 effects a separation of the contact blocks I2 to result in the drawing of a multiplicity of serially related arcs. between adjacently disposed contact blocks I2.

Since the interrupting structure is immersed in a suitable liquid, in this instance oil, the liquid penetrates the entire arcing grid chamber 5. The drawing of a multiplicity of serially related arcs between the contact blocks I2 results in an ionization of the arcing region extending between the left-hand stationary contact 9i and the right-hand stationary contact 93. A vent 9'! (see Fig. 1) is provided in the insulating end plate 4 to permit the projection therethrough of gas and products of decomposition resulting from the action of the serially related arcs upon the oil disposed in the arcing region.

Almost immediately upon the creation of a multiplicity of serially related arcs between the contact blocks I2, the arcing region within the arcing grid chamber 5 will be ionized sufficiently to result in a coalescing of the multiplicity of serially related arcs between the contact blocks I2 into a single are which extends through the arcing grid chamber 5 from the left-hand stationary contact 9i to the right-hand stationary contact 93.

After the merged arc within the arcing grid chamber 5 has been extinguished, and consequently after the electrical circuit has been interrupted through the breaker, the conducting bridging member 8| will then separate from the fingers 64, 65 to effect an additional isolating break in the circuit interrupter.

Referring more particularly to the arcing grid chamber 5 and to Figs. 4 to 9, inclusive, it will be apparent that the arcing grid chamber 5 comprises a plurality of insulating plates pressed together by the tie-rods I. It will be noticed that disposed in alternate relation and extending inwardly from the insulating base plates 3, 9 are a plurality of relatively thick U-shaped insulating plates 99, the configuration of which is more clearly shown in Figs. 4 and 5. Suitable apertures IIJI are provided in the U-shaped insulating plates 99 for the reception of the tie-rods 1. Referring more particularly to Fig. 2, it will be noticed that the bight I03 of the U-shaped insulating plate 99 extends slightly into a recess I05 grooved in the head of the contact block I2, the purpose for which will appear more fully hereinafter.

Immediately adjacent the U-shaped insulating plate 99, on both sides thereof, are two flow insulating plates I97, the configuration of which is more clearly shown in Figs. 8 and 9. The insulating plates I91 are called flow insulating plates because they permit oil disposed behind the contact blocks I2 to be spurted by the piston action of the moving contact blocks I2, around the sides I99, III] (see Fig. 1) of the contact blocks I2 and into the arcing region of the arcing grid chamber 5. The oil is thus permitted to flow along the sides I09, III] of the contact blocks I2 because of a cut-out portion III provided in the flow insulating plate I01, as more clearly shown in Fig. 8.

Immediately adjacent the two flow insulating plates I01 are four layers, each layer consisting of two strips H3, the configuration of which is more clearly shown in Figs, 6 and 7. Immediately adjacent the four layers just referred to are two flow insulating plates I01, which flow insulating plates I 01 are turned opposite to the flow insulating plates I01 previously referred to. Adjacent the two oppositely turned flow insulating plates I91 is a second U-shaped insulating plate 99, but this time also turned in the opposite direction.

The further grouping of the insulating plates is identical to that just described, namely a U- shaped insulating plate 99, two flow insulating plates I01, four layers of strips H3, two flow insulating plates I01 oppositely placed, and a U- shaped insulating plate 99 also oppositely disposed.

Referring to Figs. 4 to 9, inclusive, and also to Fig. 1, it will be apparent that the contact blocks I2, the sides of which are rectangular in form, are arranged for reciprocating motion in rectangularpassages I I3 (see Fig. 2). The sides of the rectangular passages I I3 are formed by the insulating plates previously referred to, it being noted that the cut-out portions III provided in the flow insulating plates I01 provide a bypass for oil to flow from behind the contact blocks I2 through the cut-out portions III provided in the flow insulating plates III! to the arcing region ahead of the receding contact blocks I2.

Consequently upon the opening of the breaker and the resulting lateral separation of the contact blocks I2, spurts of oil are ejected along the sides I09, II 0 of each contact block I2 into the arcing region transversely of the merged arc which at this time extends between the stationary contacts 9|, 93. The ejecting of oil from behind the contact blocks I2 upon the separation thereof, transversely of the merged arc facilitates the extinction of said merged arc.

As was mentioned previously, it is well known that in any arc rupturing device employing a chamber type structure from which a bayonettype contact is withdrawn, the interrupting efiectiveness is improved by making the contact diameter and the chamber opening as small as possible. In the embodiment of my invention being described and illustrated in Figs. 1 to 9, inclusive, the effective cross-section of the passage within the arcing grid chamber 5 extending from the right-hand stationary contact 93 to the lefthand stationary contact 9| adjacent the vent 91, may be made quite small by the utilization of the relatively thick U-shaped insulating plates 99, the bight I03 thereof extending relatively far out into the arcing region between the two stationary contacts SI, 93. Provision is made for this relatively far extension of the bight I03 of the relatively thick insulating U-s-haped plates 99, by the use of recesses I05 formed in the faces I4 of the contact blocks I2. Since, in my invention, the actual contact between adjacently disposed contact blocks I2 is formed near the sides thereof and not at the extreme end of the head. the recesses I provided in the extreme ends of the contact blocks I2 do not interfere with the current carrying capacity of the interrupter.

When the breaker shown in Fig, 1 is opened and the contact blocks I2 laterally separated to The spurts of oil resulting from the piston action of the contact blocks I2 transversely of the single merged arc, and the necessity for the single merged arc to extend in a zigzag path because of the extensions of the bights I03 of the relatively thick U-shaped insulating plates 99 into the arcing space, all combine to produce an extremely rapid extinction of the merged arc. I have interrupted 1750 amperes at 22,000 volts with only 1 cycle of arcing using an interrupter of the type shown in Fig. 1.

The method of producing extremely rapidly a single arc of relatively long dimensions 'by the production of a multiplicity of serially related arcs, which substantially immediately coalesce into a single merged arc of considerable row dimensions results in extremely effective interruption of the electrical circuit passing through the interrupting structure. The break distance required to extinguish such an arc is considerably decreased over the break distance required in conventional type circuit interrupters.

I am well aware that one of the features of my invention, namely the establishing of a long are very rapidly by first producing a multiplicity of short serially related arcs, and then merging said short arcs substantially immediately after their formation into a single merged arc, may be applied to many conventional type circuit interrupters.

The modification of my invention now to be described is illustrated in Figs. 10 to 25, inclusive, and concerns my invention as applied to a liquid type interrupter, using an interrupting structure, similar to that described in United States Patent No. 2,138,382 which issued No-" vernber 29, 1938, to Winthrop M. Leeds and Ennio Ortensi and which was assigned to the assignee of the present application.

Referring particularly to Fig. 10, there is shown an arcing grid chamber generally indi-" cated by the reference numeral I I5 placed between vertically disposed insulating support plates I, 2. Disposed within the arcing grid chamber H5 are a plurality of contact blocks I2 arranged for lateral separating motion by mechanism which may be similar to that previously described in connection with Fig. 1.

Disposed laterally to one side of the line of motion of the movable contact blocks I2 is a grid structure, which serves to attract the single merged relatively long arc extending between the stationary contact 9| 93 (see Fig. 25) to the left, as viewed in Fig. 10, and thereafter to extinguish the same. The action of the interrupting structure shown in Fig. 10 is similar to that previously described in connection with Fig. 1, but after the merged are has been formed between the stationary contacts. 9|, 93, it is moved laterally to the left, as viewed in Fig. 10,

by the biasing action exerted by a plurality of inserts II'I composed of magnetic material.

Considering Fig. 25 (which shows the breaker in the open-circuit position) with Fig. 10, it will be apparent that the arcing grid chamber II5 comprises a plurality of insulating plates suitably formed, and more clearly shown in Figs. 11 to 24, inclusive.

It will be observed that alternately disposed within the arcing grid chamber H5 and extending inwardly from the base plates II9, I2| thereof, are a plurality of relatively thick insulating plates I23, the configuration of which is more clearly seen in Figs. 11 and 12. Referring to Figs. 11 and 12, it will be noticed that the insulating plate I23 has formed therein a plurality of apertures IOI for the reception of tierods I. The insulating plate I23 is also provided with a plurality, in this instance three, oil pockets I25, which are joined together and lead into a flared vent opening I2'I.

Immediately adjacent each relatively thick insulating plate I23, on each side thereof, are two flow insulating plates I29, the configuration of which is more clearly shown in Figs. 13 and 14. It will be noticed that the now insulating plate I29 has cut-out portions |II- similar to the cut-out portions III of the flow insulating plate I0! used in the interrupter previously described in Fig. 1 and shown in Figs. 8 and 9. The \purpose of the cut-out portion III in the insulating plate I29 is the same as that previously described, namely, the provision of a plurality of spurts of oil from behind the contact blocks I2 laterally along the sides |09, IIO thereof (see Fig. 25) and into the arcing region between the stationary contacts 9|, 93.

It will also be observed that the flow insulating plates I29 also contain a plurality, in

this instance three, oil pockets I3I, the purpose for which will appear hereinafter. Immediately adjacent each set of two flow insulating plates I29 is a set of three insulating plates, the center plate of which is herein called an insert insulating plate I33 and the two outer plates of which are herein called guard insulating iplates I35. The guard insulating plates I35 are socalled because they protect the magnetic insert |I'I embedded in the insert insulating plate I33 from the direct effect of the are, which is attracted by the distortion of the magnetic field thereabout into the narrow arcing slot |3'I.

Immediately adjacent the set comprising one insert insulating plate I 33 interposed between two guard insulating plates |35, are two flow insulating plates I29 turned about as indicated by Figs. 21 and 22. Adjacent the two lastmentioned flow insulating plates I29 is a second relatively thick insulating plate I23 disposed 180 from the position of the preceding relatively thick insulating plate I23, as indicated by Figs. 23 and 24. The successive groupings of the plates are identical to the groupings just described, and consequently a further description thereof seems unnecessary.

Considering particularly Figs. 11 to 24, inclusive, it will be noticed that when the insulating plates are compressed together by the tie-rods I, the plates form a narrow arcing slot I31 as defined by the insert plate I33 and the two guard insulating plates I35. It will be noted that the narrow arcing slot I31 is only vented by the vent openings I21 provided in the relatively thick insulating plates I23 (see Figs. 11 and 12). It will be furthermore observed that the provision of th oil pockets I25 in the relatively thick insulating plates I23, and the oil pockets I3I in the flow insulating plates I29 create a readily available supply of liquid, such as oil, adjacent the are as it is moved into the narrow arcing slot I 31 along the wall thereof.

The are is not permitted to enter the narrow arcing slot I31 until the instantaneous current thereof is relatively low. Before this time the arc is compelled to remain in the enlarged arcing slot I39 of the two guard insulatin plates I35 and the insert insulating plate I33.

As was clearly brought out in the aforesaid patent, it is not advisable to attempt the interruption of an arc during the peak values of the instantaneous current thereof. The time most suitable for arc interruption is a time when the instantaneous value of the arcing current is low, that is approaching a current zero. During relatively high instantaneous values of arcing current, the cross-section of the arcing stream is too large to permit it to be forced into the narrow arcing slot I31, and it is consequently positioned adjacent the entrance thereto in the enlarged arcing slot portion I39. Because of the presence of the magnetic inserts H1 in the insert insulating plates I33, the magnetic field surrounding the arc stream is distorted and the arc stream is constantly biased into the narrow arcing slot I31 by a force which varies as a function of the instantaneous value of the arcing current. When the instantaneous value of the arcing current reaches a relatively low magnitude, the cross-sectional area of the arc stream is sufliciently small so that the biasing action exerted by the magnetic inserts H1 is sufiicient to move the arc laterally into the narrow arcing slot I31 to effect its extinction.

While the arc is positioned in the narrow arcing slot I 31, it reacts upon the oil disposed in the oil pockets I3I in the flow insulating plates I29 and the pockets I25 disposed in the relatively thick insulating plates I23 to result in a production of a quantity of gaseous and liquid particles,

fication the eifective cross-sectional path between the stationary contacts 9I, 93 (see Fig. 25) may be made quite small to increase the interrupting effectiveness of the breaker by the use of the relatively thick insulating plates I23 extending a considerable distance into the arcing path between the stationary contacts 9|, 93. Again, notches or recesses I95 may be necessary in the faces of the contact blocks I2 to accommodate the extension of the relatively thick insulating plates I23.

Another modification of my invention is shown in Figs. 26 and 27. In this modification of my invention, instead of having two stationary contacts (such as 9|, 93 in Figs. 1 and 25) I employ a stationary contact MI and a movable contact I43. When the breaker is in the closed circuit position (not shown) the movable contact I43 engages the lower contact block I2, the electrical circuit passing through the interrupter then comprising the movable contact I43, the plurality of bridging contact blocks I2, the stationary contact MI and an external flexible line conductor I45.

When the breaker is opened, there is a simultaneous downward movement of the movable contact I43 with the lateral separating movement of the contact blocks I2. Any suitable mechanism may be employed to effect this simultaneous movement. For instance, that which is used in the present modification comprises an insulating ofi standing member I 41 which actuates two bell crank levers I49 which are pivotally connected to the insulating operating links I 5I. The insulating operating links I5I are pivotally connected to the insulating operating blocks I53, I 55, in which are embedded the operating rods I3 of the contact blocks I2. The bell crank levers I49 are biased to the open-circuit position by tension springs I51.

It will consequently be apparent that when it is desired to close the breaker, the movable contact I43 is actuated upwardly, and the insulating member I 41 attached thereto actuates the V exerted by the tension springs I51, to effect a simultaneous movement of the movable contact I43 and of the contact blocks I2.

In the closed-circuit position of the inter- Which pass transversdy through the are Stream 60 rupter, indicated by the dotted lines in Fig. 27,

and out of the narrow arcing slot I 31 through the vent openings I21 provided in the insulating plates I23. i

The deionizing action of the liquid and gaseous particles passing transversely through the arc stream while it is positioned in the narrow arcing slot I31, and the constriction afforded by the walls of the narrow arcing slot I31, as formed by the insert insulatin plate I33 and the two guard insulating plates I35 in each grouping, affords a very effective extinguishing action upon the arc to result in the extinction thereof. It will be noticed that the arc itself is never permitted to pass out of the narrow arcing slot I31 because the vent openings I21 are only provided in the relatively thick insulating plates I23. It will also be apparent that the deionizing activity of the arcing grid chamber H5 is increased by the spurting of oil into the arcing region by the piston action created by the movement of contact blocks I2.

It will be observed that there is no vent opening in the arcing grid chamber H5 corresponding to the vent opening 91 provided in the structure illustrated in Fig. 1. In the present modiit will be noticed that instead of the line contact between the contact blocks I2, as was the case in the previous two embodiments of my invention, there is an abutting engagement between the contact blocks I2, and also between the contact blocks I2 and the stationary and movable contacts I4I, I43. The current carrying capacity of the breaker is hence improved by utilizing an abutting engagement of the contact blocks I2 with the stationary and movable contacts I4I, I43.

The present modification of my invention concerns an interrupter of the air-break type in which is provided gas-evolving material, in this instance, such as the inwardly extending bafiles I59 composed of a suitable gas-evolving material, such as boric acid, horn fiber or other resinous material. It will be noticed that in this modification of my invention the baffles I 59 extend considerably inwardly so that the single merged are between the stationary contact I4! and the movable contact I43 will be brought into intimate engagement with the inner ends I6I of the baffles I 59. By such an intimate engagement between the arc and the inner ends I61 of the gas-evolving bafiles I59, there is produced a voluminous amount of arc extinguishing gas, which passes axially downward through the breaker to the vent opening I63 at the lower end of the arcing chamber. It will be noticed however, that before the arc extinguishing gas produced by the action of the arc upon the baffles I59 can pass out of the interrupting structure through the vent opening I63, it must necessarily traverse a zigzag path which is substantially perpendicular to the direction of the arc stream when the latter extends between the stationary contact MI and the movable contact I43. There is thus consequently produced a very effective extinguishing action of the gas evolved.

Again, in this modification of my invention, the effective cross-sectional area of the arcing passage extending between the stationary contact MI and the movable contact I43 through the grid structure may be dimensioned to improve the interrupting capacity of the breaker by the inward extension of the baflles I59, but because of the abutting engagement of the contact blocks I2 and the provision of recesses I05, the current carrying capacity of the interrupter is not impaired.

When the breaker is in the open circuit position, there is provided an isolating gap in the electrical circuit passing through the breaker because of the downward movement of the movable contact I43. Upon the downward movement of the movable contact I43, the tension springs I51 effect a lateral separation of the contact blocks I2 to draw a plurality of serially related arcs between the contact blocks I2, and the contact blocks I2 to the stationary and movable contact I4I, I43. Immediately thereafter, however, the plurality of serially related arcs coalesce into a single merged are extending in a somewhat zigzag manner from the stationary contact IM to the movable contact I43. The production of arc extinguishing gas, as previously described, and the passage thereof transversely through the arc stream, and the diminishment of the efiective cross-sectional path through the grid structure from the stationary contact MI to the movable contact I43, all contribute to result in an effective extinguishment of the merged arc.

My invention may be incorporated in other airtype breakers, or breakers of the type utilizing a blast of compressed gas with the provision of suitable vents provided along the arc passage. The gas blast may be transverse or longitudinal of the arc stream and may be supplied from pumps or other means to assist in the extinction of the are established by separating contacts of the breaker.

When my invention is utilized in a liquid type breaker, liquid pumps may be utilized and suitable vents provided for the flow of liquid transversely or longitudinally of the arc stream to effact its extinction. Many other modifications and applications of my invention will readily suggest themselves to one skilled in the art.

It will be apparent from the foregoing that, I have provided an interrupter which very rapidly produces a single merged arc of considerable length by an initial formation of a plurality of serially related arcs and the substantially immediately merging of said serially related arcs by the ionization of the arcing region through the breaker. This method of producing a long are of considerable length very rapidly may be used in conjunction with conventional interrupting structures to assist in the extinction of the arc,

or it may be used in air-type breakers of the gas evolving type.

Although I have shown and described specific circuit interrupting structures, it is to be understood that the same were merely for purposes of illustration and that changes and modifications may be made by those skilled in th art without departing from the spirit and scope of the appended claims.

I claim as my invention:

1. The method of interrupting an electrical circuit comprising initially forming a plurality of relatively short serially related arcs, merging said arcs into a single arc of considerable length, and then extinguishing said single merged arc of considerable length.

2. The method of interruptingan electrical circuit comprising first producing a plurality of closely spaced break in said circuit to form a plurality of relatively short serially related arcs, causing the coalescence of said relatively short serially related arcs into a single are of considerable length, and extinguishing said single arc of considerable length by deionizing activity.

3. In a circuit interrupter, relatively movable contact structure movable to first form a plurality of relatively short serially related arcs, means to merge said plurality of relatively short serially related arcs into a single arc of considerable length, and means for extinguishing said merged arc.

4. In a circuit interrupter, a plurality of alternately disposed cooperating contact blocks, said contact blocks being separable to form a plurality of relatively short serially related arcs, means for coalescin said plurality of relatively short serially related arcs into a single arc of relatively long length, and means for extinguishing said single arc.

5. In a circuit interrupter, a substantially closed arcing chamber, one or more first contact blocks disposed within said arcing chamber and arranged for simultaneous lateral motion, a plurality of second contact blocks disposed within said chamber and arranged for simultaneous lateral motion, said first and said second contact blocks being alternately disposed with respect to each other and separable simultaneously to form a plurality of relatively short serially related arcs within said chamber, means for merging said plurality of relatively short seriall related arcs into a single arc of considerable length, and means for extinguishing said merged arc.

6. In a circuit interrupter, a substantially closed arcing chamber, one or more first contact blocks disposed within said arcing chamber and arranged for simultaneous lateral motion, a plurality of second contact blocks disposed within said chamber and arranged for simultaneous lateral motion, said first and said second contact blocks being alternately disposed with respect to each other. and a plurality of insulating bafile members disposed within said arcing chamber.

'7. In a circuit interrupter, a substantially closed arcing chamber, one or more first contact blocks disposed within said arcing chamber and arranged for simultaneous lateral motion, a plurality of second contact blocks disposed within said chamber and arranged for simultaneous lateral motion, said first and said second contact blocks being alternately disposed with respect to each other, said first and said second contact blocks being arranged for simultaneous lateral separatin motion to form a plurality of relatively short serially related arcs, means for merging said plurality of relatively short serially related arcs into a single arc of considerable length, a plurality of insulating baffles alternately disposed within said chamber and extending from the lateral inner walls of said chamber inwardly to a point adjacent the axis of said chamber, said first and said second contact blocks having recesses to accommodate the inner ends of said baflles.

8. In a circuit interrupter, a substantially closed arcing chamber, stationary contact means disposed at opposite ends of said arcing chamber, one or more first contact blocks disposed within said chamber and arranged for simultaneous lateral motion, a plurality of second contact blocks alternately disposed with respect to said one or more first contact blocks and also arranged for simultaneous lateral motion, said first and said second contact blocks abutting each other in alternate relation along the axis of said chamber extending between said stationary contact means in the closed-circuit position of said interrupter, said first and said second contact blocks being simultaneously separable during the opening of said interrupter to form a plurality of relatively short serially related arcs, said plurality of relatively short serially related arcs merging into a single are extending between said stationary contact means.

9. In a circuit interrupter, a substantially closed elongated arcing chamber, a stationary contact disposed at one end of said chamber, asecond stationary contact disposed at the other end of said chamber, a vent disposed adjacent one of said stationary contacts, one or more contact blocks disposed within said chamber and arranged for simultaneous lateral motion, a plurality of second contact blocks disposed within said chamber and arranged for simultaneous lateral motion, said first and said second contact blocks being alternately disposed with respect to each other and simultaneously movable toward and away from each other, a plurality of insulating baflles extending from the inner lateral walls of said chamber to a point adjacent the axis of said elongated chamber, each contact block movable between two insulating bafiles, said contact blocks being cooperable to form a plurality. of relatively short serially related arcs, said plurality of relatively short serially related arcs merging into a single arc extending between said stationary contacts, and means for extinguishing said merged are by a fluid blast through the axis of said chamber and out of said vent.

10. In a liquid break circuit interrupter, a substantially closed arcing chamber, one or more first contact blocks arranged for lateral motion, a plurality of second contact blocks also arranged for lateral motion, said first and said second contact blocks engaging in abutting relation in the closed-circuit position of said interrupter, a piston chamber associated with one or more of said contact blocks so that upon the lateral separating motion of one or more of said contact blocks liquid within said piston chamber is spurted around the sides of the contact block associated with said piston chamber into the arcing region.

11. In a liquid break circuit interrupter, an arcing chamber, a plurality of alternately disposed contact .blo-cks within said chamber, means for separating said plurality of alternately disposed contact blocks to form a plurality of relatively short serially related arcs, and means utilizlng the separating motion of said contact blocks for spurting liquid into the arcing region.

12. In a liquid break circuit interrupter, a substantially closed elongated arcing chamber disposed in an arc extinguishing liquid, a stationary contact positioned at one end of said arcing chamber, a second stationary contact disposed at the other end of said arcing chamber, a vent adjacent one of said stationary contacts, a plurality of operating rods extending through a lateral wall of said chamber and arranged for simultaneous reciprocating lateral motion, each operating rod carrying at its inner end a rectangular contact block with a recessed head, a plurality of second operating rods. extending through the opposite lateral wall of said chamber and also arranged for simultaneous reciprocating motion, each of said second operating rods carrying at its inner end a rectangular contact block with a recessed head, said contact blocks arranged to engage in abutting relationship in the closedcircuit position of said interrupter with each other and also with said two stationary contacts to provide a current carrying path through said interrupter, insulating bafile structure disposed within said chamber and interposed between adjacent ontact blocks, part of said balile structure being accommodated by said recesses in said contact heads, said bafiie structure also providing a piston chamber associated with each rectangular contact block so that upon the lateral separating motion thereof liquid disposed behind said contact block will be spurted in front of said contact block along the sides thereof into the arcing region, said contact blocks being separable to form a plurality of relatively short serially related arcs which subsequently merge into a single are extending between said two stationary contacts, a blast of gas and liquid particles longitudinally,v of said arcing chamber and through said vent assisting in the extinguishing of said single merged arc.

13. In a circuit interrupter, means for initially forming a plurality of serially related arcs, means for merging said plurality of serially related arcs into a single arc of considerable length, and means for eiiecting a lateral transfer of at least a part of said single merged arc to effect its extinguishment.

14. In a circuit interrupter, an arcing chamber, an adjacently disposed interrupting structure, means for first forming a plurality of relatively short serially related arcs within said arcing chamber, means for merging said plurality of serially related arcs into a single arc of considerable length within said arcing chamber, means for effecting a lateral transfer of at least a part of said single merged are into said interrupting structure to efiect therein the extinguishment of said single merged are.

15. In a circuit interrupter of the liquid break type, an arcing chamber, relatively movable contact structure disposed within said arcing chamber, said contact structure being movable to first form a plurality of serially related arcs of relatively short length, means for merging said plurality of serially related arcs into a single arc of extensive length, insulating bafile structure forming an adjacently disposed elongated arcing slot, and means for efiecting a lateral transfer of at least a part of said merged arc into said elongated arcing slot to effect therein the extinction of said merged arc.

16. In a circuit interrupter, a substantially closed arcing chamber, a stationary contact at one end of said arcing chamber, an opening at the opposite end of said arcing chamber, a movable contact movable through said opening in the closed-circuit position of said interrupter, and relatively movable contact structure disposed within said chamber and cooperable with said stationary contact and with said movable contact to first form a plurality of serially related arcs during the opening operation of said interrupter, said plurality of serially related arcs merging into a single arc of considerable length extending between said stationary contact and said movable contact.

17. In a circuit interrupter, an arcing chamber, relatively movable contact structure movable to initially cause the formation of a number of short serially related arcs, means for merging said arcs into a single arc of considerable length, and

insulation means disposed adjacent the region of formation of said arcs and said single merged are, said insulation means being at least in part gas-evolving in the presence of an are.

18. In a circuit breaker of the gas-evolving type, a substantially closed arcing chamber, a stationary contact at one end of said arcing chamber, an opening in the opposite end of the arcing chamber, a movable contact; movable through the opening in the opposite'end of said arcing chamber, laterally separable alternately disposed contact means to bridge said stationary and said movable contact in the closed-circuit position of said interrupter, baffle structure disposed in said arcing chamber to decrease the effective cross-section of the arc extinguishing passage between said stationary contact and said movable contact, said baflle structure being composed in part of gas-evolving insulating material, said contact means being separable simultaneously with the opening movement of said movable contact to first form a plurality of relatively short serially related arcs which substantially immediately merge into a single are extending between said stationary contact and said movable contact, said single merged are being extinguished with the help of the gas evolved from said bafile structure.

19. In a circuit interrupter, a stationary contact, a movable contact, a plurality of alternately disposed laterally separable contact blocks which conductively bridge said stationary contact and said movable contact in the closed-circuit position of said interrupter, said contact blocks being simultaneously movable to initially form a plurality of serially related arcs which substantially immediately merge to form a single are extending between said stationary and said movable contacts, the lateral separating motion of said contact blocks taking place at the same time the movable contact is being moved to the open circuit position.

20. In a circuit interrupter, a substantially closed chamber, a stationary contact disposed at one end of said chamber, an opening at the other end of said chamber, a movable contact movable through said opening, an arc passage extending between the stationary and movable contacts, and insulating bafile means disposed within said chamber to decrease the effective cross-section of the arc passage extending between said stationary and said movable contacts.

21. In a circuit interrupter, a first contact structure, a second contact structure, both said contact structures arranged for reciprocal motion toward and away from each other to open and close the circuit through said interrupter, a first pivoted lever, a second pivoted lever, both levers being pivoted intermediate their ends, said first contact structure being connected to one end of said first pivoted lever, said second contact structure being connected to one end of said second pivoted lever, and biasing means for urging the free ends of both said pivoted levers toward each other to bias said interrupter to the open-circuit position.

22. In a circuit interrupter, a first contact structure, a second contact structure, said two contact structures arranged for reciprocal motion toward and away from each other to open and close the circuit through said interrupter, a first pivoted lever, a second pivoted lever, both levers being pivoted intermediate their ends, said first contact structure being connected to one end of said first pivoted lever, said second contact structure being connected to one end of said second pivoted lever, spring means for biasing the free ends of said first and second pivoted levers toward each other, a contact member, said contact member being movable to extend said spring means to efiect a rotation of both said pivoted levers and a consequent closing motion of said first and second contact structures.

23. In a circuit interrupter, a first contact structure, a second cooperable contact structure, both said contact structures being arranged for reciprocal motion toward and away from each other to open and close the circuit through said interrupter, a first pivoted lever, a second pivoted lever, said first contact structure being connected to one end of said first pivoted lever, said second contact structure being connected to one end of said second pivoted lever, a third pivoted lover, a tension spring connecting the free end of said first pivoted lever to one end of said third pivoted lever, a link member connecting the free end of said second pivoted lever to the same end of said third pivoted lever that one end of said tension spring is fastened to, a contact block pivotally connected to the free end of said third pivoted lever, a contact member, a fourth lever pivoted at one end, the free end of said fourth lever being connected to said contact block to produce linear motion thereof, said contact member operable to engage said contact block to effect an extension of said tension spring to produce rotation of said first and said second pivoted levers to close the interrupter.

'24. In a circuit interrupter, a stationary contact, a movable contact, a first laterally movable contact structure, a second laterally movable contact structure, both said contact structures arranged for reciprocal lateral motion toward and away from each other to effect opening and closing of the circuit through said interrupter, a first pivoted lever, a second pivoted lever, said first contact structure being connected to one end of said first pivoted lever, said second contact structure being pivoted to one end of said second pivoted lever, an offstanding member secured to said movable contact to engage the free ends of said first and second pivoted levers to effect a closing motion of said first and second contact structures simultaneously with a closing motion of said movable contact.

25. The method of interrupting an electrical circuit comprising first establishing and lengthening a plurality of relatively short serially related arcs, merging the arcs into a single arc of shorter length than the combined length of the separate arcs, and subjecting at least a portion of the merged arc to are extinguishing action to effect its extinction.

26. In a circuit interrupter, one or more first movable blunt nosed contact blocks arranged for lateral motion, a plurality of second movable blunt nosed contact blocks also arranged for lateral motion, said first and said second contact blocks being alternately disposed with respect to each other and separable to form a plurality of relatively short serially related arcs.

27. In a circuit interrupter, one or more first contact blocks arranged for lateral motion, a plurality of second contact blocks also arranged for lateral motion, said first and said second contact blocks being alternately disposed with respect'to each other and separable to form a plurality of relatively short serially related arcs, the plurality of relatively short serially related arcs merging into a single arc of substantial length following continued separation of the first and second contact blocks.

28 In a circuit interrupter, a first movable contact means, a second movable contact means, the first and second movable contact means being engageable in the closed circuit position of the interrupter, both the first and second contact means being movable to result in separation between the first and second contact means to produce thereby a plurality of relatively short serially related arcs, and means utilizing the motion of the first and second contact means to force are extinguishing fluid toward the arcs.

29. In a circuit interrupter, a first contact means, a second contact means, the first and second contact means being engageab-le in the closed circuit position of the: interrupter, both the first and. second contact means being movable to result in separation between the first and second contact means to produce thereby a plurality of relatively short serially related arcs, the plurality of relatively short serially related arcs merging into a single arc of considerable length upon continued opening movement of the first and second contact means.

30. The method of interrupting an electrical circuit comprising first establishing a plurality of relatively short serially related arcs, merging the arcs into a single are by raising their are voltages, and subjecting at least a portion of the merged arc to arc extinguishing action to efiect its extinction.

31. The method of interrupting an electrical circuit comprising first establishing a plurality of relatively short serially related arcs, raising the are voltage of each of the short arcs so as to cause them to merge into a single relatively long are of lower total are voltage, and then subjecting at least a portion of the merged arc to are extinguishing action to effect its extinction.

WINTHROP M. LEEDS. 

